Electrical connector and switching device

ABSTRACT

The housing of an electrical device has connector sockets on one side and connector plugs on the opposite side. The housing comprises a backplate and a front plate each made of molded plastic material. The backplate has integral ledge members. The front plate, which is preferably transparent, to reveal the interior, is placed on top of the ledge members and has integrally formed tubular and full-bodied rivets which pass through the ledge members and have their ends secured in corresponding recesses on the backface of the backplate. The ledge members surround a switching chamber within the housing. A switching bridge is movable in the chamber between two switching positions and is engageable with fixed contacts depending upon the position occupied at a time. The fixed contacts comprise sheet-metal strips each having a curved shape at three localities along its length, the end of each strip extending through the ledge members to the outside of the housing so as to form one of the connector plugs of the device. Terminal screws are in threaded engagement with corresponding strips in the housing, but are accessible from the outside. A spring-biased tappet is longitudinally displaceable between the connector plugs and in parallel relation thereto for actuating the switching bridge. The tappet extends to the outside of the housing when the bridge is in one of its limit positions, so that the tappet can then be actuated directly or by engagement with the tappet of an analogously designed device. Two or more such devices can be plugged together to form a desired switching or connection arrangement.

United States Patent [72] Inventors Fritz Mantel Frankfurt am Main;

Rolf A. Maia, Amberg, both of, Germany [21] Appl. No. 9,150

[22) Filed Feb. 6, 1970 [45] Patented June 22, 1971 [73] Assignee Voigt & llaefiner G.m.b.l1.

Frankfurt, Germany [$4] I ELECTRICAL CONNECTOR AND SWITCHING OTHER REFERENCES Machat, German App. No. 1,050,861, publ. 2- 59, l sht. dwg. 2 pp. spec. (copy 200- 168S(ux) Kohn, German App. No. 1,245,471, publ. 7 67, 1 sht. dwg. 2 pp. spec. (copy 200- 166B3(UX)) Primary ExaminerDavid Smith, Jr. Attorneys-Curt M. Avery, Arthur E. Wilfond, Herbert Lv Lerner and Daniel .1. Tick ABSTRACT: The housing of an electrical device has connector sockets on one side and connector plugs on the opposite side. The housing comprises a backplate and a front plate each made of molded plastic material. The backplate has integral ledge members. The front plate, which is preferably transparent, to reveal the interior, is placed on top of the ledge members and has integrally formed tubular and full-bodied rivets which pass through the ledge members and have their ends secured in corresponding recesses on the backface of the backplate. The ledge members surround a switching chamber within the housing. A switching bridge is movable in the chamber between two switching positions and is engageable with fixed contacts depending upon the position occupied at a time. The fixed contacts comprise sheet-metal strips each having a curved shape at three localities along its length, the end of each strip extending through the ledge members to the outside of the housing so as to form one of the connector plugs of the device. Terminal screws are in threaded engagement with corresponding strips in the housing, but are accessible from the outside. A spring-biased tappet is longitudinally displaceable between the connector plugs and in parallel relation thereto for actuating the switching bridge. The tappet extends to the outside of the housing when the bridge is in one of its limit positions, so that the tappet can then be actuated directly or by engagement with the tappet of an analogously designed device. Two or more such devices can be plugged together to form a desired switching or connection arrangement.

ELECTRICAL CONNECTOR AND SWITCHING DEVICE thus forming a series of mutually adjacent components, may

be controlled by a single operation or a single control member. In conjunction therewith, it is a more specific object to devise a system of such plug-connectable units which affords, by a corresponding selection of normally closing or normally opening switches, to perform or release the largest feasible number of different switching functions.

It is another object of our invention to design the housing of the device in such a manner that it consists of a minimum number of parts which can be assembled and fastened together by particularly simple means.

further object of the invention is to provide devices of the aforedescribed type with openings which extend through the device so as to permit cables or bolts to pass therethrough.

It is also an object of our invention, relating to devices generally of the aforedescribed type, to locate all the components which cooperate in the performance of switching operations .into the housing from one and the same side thereof and topermit fastening these components from the same side. It is a subsidiary object to have the positioning and fastening of these components remain visible so that their proper arrangement, connection and functioning may be supervised by visual inspection. I

It is a furtherobject of the invention to pennit the use of the fixed switch contacts arranged in the housing as connecting conductors for several connections which are suitable not only for a plug in connection, but also for receiving cable shoes, or for the attachment of connector cables by means of screws.

Another object of the invention is to provide a safe latching or catching of the plug pinsin the sockets into which they are inserted.

Furthermore, the invention aims at providing devices which, aside from one or more of the foregoing objects, may be utilizedas limit switches, door switches, and the like. To achieve these objects, and in accordance with our invention, the housing of our electrical device comprises two main parts, namely a backplate of plastic material with ledge members, integrally molded together with the backplate and protruding therefrom, and a' preferably transparent front plate, also of plastic material, which has integrally molded rivet members. The front plate is placed on top of the ledge members and the rivets of the front plate pass through corresponding openings of the ledge members to the opposite face of the backplate where the rivets are molded into recesses of the backplate,

thus holding the two plates tightly together. The two plates and the ledge members conjointly form the housing and the corresponding cavities in which the electrical socket members, the 'plug connector members, and the components of a switching device are accommodated. More specifically, the ledge members surround a switching chamber in which a switching bridge is movable between two positions and is engageable with fixed contacts in a selected position. Each of the fixed contacts comprises a sheet-metal strip having a curved shape at three localities along its length. The ends of each strip extend to'outside the housing to form one of the connector plugs of the device. A terminal screw is in threaded engagement with the middle portion of each strip and is accessible from outside the housing. A spring-loaded tappet is longitudinally displaceable in the housing between the connector plugs and is in parallel relation with the plugs and controls the movements of the switching bridge. The tappet extends to out- I side the housing when the bridge is in one of its switching positions. The tappet may thus be actuated directly or by the tappet of an adjacent device plugged together with the one described. Conversely, the tappet may engage the tappet of an adjacent device and thus control the latter.

It is preferable to provide the plug pins with lateral recesses and to provide the connector sockets of a device according to the invention with wire springs designed for catching the corresponding recesses of the plug pins of an adjacent plugged-in device of similar type. v

The terminal screws in the housing may serve for the at tachment of cable shoes within the housing and/or for the fastening of additional plug pins which have a bent or curved shape and a sufficient length to extend to outside the housing.

The invention will be further described with reference to embodiments thereof which are illustrated by way of example in the accompanying drawings, in which:

FIG. I is a front view of an embodiment of a device of the invention designed as a normally open switch with a rigid switching bridge;

FIG. 2 is a lateral elevation seen from the top of FIG. 1;

FIG. 3 is a cross-sectional view, taken along the lines III-III of FIG. I;

FIG. 4 is a cross-sectional view, taken along the lines IV-IV of FIG. 1;

FIG. 5 is a front view of an embodiment of a device of the invention designed as a normally closed switch with a ridgeswitching bridge; 7

FIG. 6 is a front view of an embodiment of a normally open switching device of the invention with snap-action bridge members; and 1 FIG. 7 is a front view, similar to that of FIG. 6, of an embodiment of a snap-action switch device of the invention which is normally closed.

Details of the normally open switch device of FIGS. 1 to 4 are hereinafter described, and such details are in the devices of FIGS. 5 and 6, with the exception of the modifications hereinafter described.

A housing of the device comprises a backplate 1 with integral ledge members 20, 2b, 2c, and 2d which protrudes from the backplate proper and are formed conjointly therewith as a single piece by injection molding. Molded into the ledge members are recesses 3a and 3b, which form the socket openings of the device. A front plate 4 of transparent plastic is placed face to face onto the tops of the ledge members 2a, 2b, 2c and 2d.

The front plate 4 is also molded from plastic material and conjointly with integral rivets 5a and 5b and hollow or tubular rivets 6a and 6b; the molding being preferably done by injection molding. The rivets 5a and 5b and 6a and 6b pass through openings of the ledge members 2a, 2b, 2c and 2d and are molded at their ends into recesses 7a and 7b, respectively, 8a and 8b, respectively, one of which is shown in FIG. 3 and the other of which is shown in FIG. 4, at the backface of the backplate 1, thus joining the two parts of the housing tightly and firmly together.

The ledge members 20 to 2d surround a switching chamber 9 in which a switching bridge 10 and fixed switch contacts 11a and 11b are arranged..Each of the switch contacts 11a and 11b is a sheet-metal strip of angular shape, curved at three places spaced from each other along the length of the strip. The ends of each strip extend out of the ledge members and out of the confines of the housing so as to form the plug pins Ila and 11b, respectively, of the device.

The two plug pins 11a and llb of FIG. 1 are spaced from each other the same distance as the two sockets 3a and 3b on the opposite side of the housing and are arranged in symmetrical relation to the vertical center axis of the device, as shown in FIG. 1. It will be recognized, therefore, that a second device of the same design may be joined with the one illustrated by plugging the pins of the second device into the sockets 3a and I Terminal screws [30 and 13b are in threaded engagement with the middle portion of each corresponding strip which forms a fixed contact lIa and 11b of the plug pins 11a and llb. The terminal and clamping screws 13a and 13b, although located within the confines of the housing, are freely accessible from the outside, namely from the lower left side and lower right side of the device of FIG. I. Connector wires or cables may be directly fastened to the strips Ila and III) by means of the screws 13a and I3b. However, as shown in FIG. 1, a cable shoe 14 may be seated on one or both of the screws for thus fastening a cable to the corresponding strip. FIG. I also shows an additional plug pin I which has a seat or eye portion seated on the right-hand terminal screw 13b and thus is fastened to the corresponding strip. The pin 15 is of angular shape and extends beyond the confines of the housing to the outside.

'A tappet 17 extends between the sockets 3a and 3b and the plug pins Ila and llb. The tappet 17 is guided by and between the ledges 2a, 2b, 2c and 2d, loaded by a biasing spring 16, and which carries the switching bridge I0. The tappet 17, in the illustrated open position of the bridge (FIG. I), protrudes from the housing at the top side thereof, as illustrated in FIG. 1, whereas in this position the tappet is fully located within the confines of the housing. A somewhat broadened recess I8 formed by the ledge members 2b and 2c serves for receiving the protruding portion of a tappet which may form part of an adjacent device whose sockets are engaged by the plug pins 1 la and I lb.

In order to permit such a series plug in connection of two or more devices of similar type, the spacing between the sockets 3a and 3b is the same as between the plug pins 11a and 11b and each socket is aligned with a corresponding one of the pIIIS.

Each of the plug pins lla and 11b and the additional plug pin has a lateral notch, recess or bore 19a, 19b and 190, respectively. Wire springs 20a and 20b are placed in cavities of the ledge members 20 and 2d, respectively, so that the legs of each wire spring are located on opposite sides of the corresponding one of the socket openings 3a and 3b in order to catch into the recess 19a and 19b of an inserted plug pin 11a and 11b, respectively, appertaining to an adjacent device, when the latter device is plug-connected with the one shown.

As will be seen, all parts 10, Ila, llb', Ila and 11b, together with such parts as 13a and 13b and 14 which may also serve to perform or coact in electrical function may be placed from one and the same side into the corresponding recesses or cavities of the ledge members 20 to 2d. This also applies to the tappet 17. Once these parts are placed in proper position, and the top plate is fastened to the backplate, the positioning of all parts within the housing is secured by the backplate I and its ledge members 2a to 2d, as well as by the front plate 4, so that no further fastening means are needed.

The backplate and the front plate 4 are held together exclusively by the rivets 5a and 5b and 6a and 6b. The tubular rivets 6a and 6b are available for the passage of wires or cables. The tubular rivets 6a and 6b may serve to receive mounting screws if the device is to be fastened to a panel or wall, In such case,

either the bacLplate or the front plate may face the panel or wall.

The device illustrated in FIG. 5 corresponds essentially to the device described with reference to FIGS. I to 4. The only difference is that a rigid switching bridge of FIG. 5 is normally held in engagement with the fixed contacts by the biasing force 'of a spring so that the switch is normally closed. The devices illustrated in FIGS. 6 and 7 are to a large extent also identical with the device described with reference to FIGS. I to 4, but are equipped with snap-action bridge contacts a and 30b (FIG.-6) and 31a and 31!: (FIG. 7). The device of FIG. 6 has normally open contacts, whereas the corresponding device of FIG. 7 has normally closed contacts. In both devices, the appertaining tappet 17" is provided with a carrier 33 which has notches serving as pivots for the ends of the two snap-action switch arms 30a and 3012 or 31a and 31b. The carrier 33 comprises a substantially Ushaped spring which engages the two snap-action arms 30a and 30b or 31a and 31 b of each switching bridge at about the middle thereof. The bight portion of the spring 33passes through a recess in the tappet 17". I

It will be understood that the particular size and geometric shape of the device may be varied within wide limits, but, while the size is not essential to the invention, it is advantageous that devices accordingto the invention lend themselves readily to being given very small dimensions without causing undue inconvenience with respect to the manufacture of the parts, the assembling of the parts and the use of the device. For example, devices as shown on the drawings have been made in a square configuration of 30 mm. edge length.

The circuit components to be controlled by a device according to the invention can be electrically connected thereto by means of the terminal screws 13a, 131; or cable shoes 14 or plug pins I5, unless such components form part of the circuits connected by means of the sockets 3a, 3b or plug pins lIa, llb. Such controlled components may be separate from the controlling devices or may be mounted on the backplate I or front plate 4 of the housing, the latter way of mounting being applicable, for example, to signal lamps or relays.

Upon a study of this disclosure it will be obvious to those skilled in the art that with respect to structural details our invention permits of various modifications and may be given embodiments other than those illustrated and described herein, without departing from the essential features of the invention and within the scope of the claims annexed hereto.

We claim:

I. An electrical device having a housing with connector sockets on one side and connector plugs on the opposite side of the housing, said housing comprising a backplate of plastic material with ledge members integral with the backplate and protruding therefrom, and a front plate of plastic material placed on top of said ledge members and having rivet members integral with said front plate and passing through said ledge members and partly through said backplate, said backplate having recesses and each of said rivet members having molded ends fasteningly seated in a corresponding one of said recesses, said housing forming a switching chamber surrounded by said ledge members between said backplate and said front plate; a switching bridge arranged in said chamber and movable therein between two bridge positions; fixed contacts arranged in said chamber for engagement by said switching bridge, each of said fixed contacts comprising a sheet metal strip having a curved shape at mutually spaced localities along its length and having an end extending through said ledge members to the outside so as to form said connector plugs of the device; terminal screws each in threaded engagement with a corresponding one of said strips at the middle portion thereof and accessible from outside said housing; and a spring biased tappet longitudinally displaceable in said housing between said connector plugs and parallel to said plugs, said switching bridge being affixed to said tappet in a manner whereby said bridge is actuated by movement of said tappet, said tappet extending to outside said housing when said bridge is in one of its bridge positions.

2. A device as claimed in claim I, wherein said front plate is transparent for visual inspection of the internal arrangement of components.

3. A device as claimed in claim 1, wherein said tappet protrudes from said housing at one side thereof when said tappet and bridge are in the spring-biased position, and said tappet is substantially entirely within the confines of said housing when said tappet and bridge are in the other position.

4. A device as claimed in claim 1, wherein said connector sockets of said housing are spaced from each other the same distance as the corresponding connector plugs and each of said connector sockets is aligned with a corresponding one of said connector plugs, whereby any number of said electrical devices are adapted to be plugged together in series.

5. A device as claimed in claim 1, further comprising a cable shoe arranged substantially in said housing and seated on one of said terminal screws whereby said shoe is fastened to one of said strips.

6. A device as claimed in claim 1, further comprising a plug pin having a seat portion seated on one of said terminal screws and fastened thereby to one of said strips, said plug pin having a generally angular shape and extending from said screw to outside said housing.

7. A device as claimed in claim 2, wherein said rivet members are located on each side of said tappet and comprise at 

1. An electrical device having a housing with connector sockets on one side and connector plugs on the opposite side of the housing, said housing comprising a backplate of plastic material with ledge members integral with the backplate and protruding therefrom, and a front plate of plastic material placed on top of said ledge members and having rivet members integral with said front plate and passing through said ledge members and partly through said backplate, said backplate having recesses and each of said rivet members having molded ends fasteningly seated in a corresponding one of said recesses, said housing forming a switching chamber surrounded by said ledge members between said backplate and said front plate; a switching bridge arranged in said chamber and movable therein between two bridge positions; fixed contacts arranged in said chamber for engagement by said switching bridge, each of said fixed contacts comprising a sheet metal strip having a curved shape at mutually spaced localities along its length and having an end extending through said ledge members to the outside so as to form said connector plugs of the device; terminal screws each in threaded engagement with a corresponding one of said strips at the middle portion thereof and accessible from outside said housing; and a spring biased tappet longitudinally displaceable in said housing between said connector plugs and parallel to said plugs, said switching bridge being affixed to said tappet in a manner whereby said bridge is actuated by movement of said tappet, said tappet extending to outside said housing when said bridge is in one of its bridge positions.
 2. A device as claimed in claim 1, wherein said front plate is transparent for visual inspection of the internal arrangement of components.
 3. A device as claimed in claim 1, wherein said tappet protrudes from said housing at one side thereof when said tappet and bridge are in the spring-biased position, and said tappet is substantially entirely within the confines of said housing when said tappet and bridge are in the other position.
 4. A device as claimed in claim 1, wherein said connector sockets of said housing are spaced from each other the same distance as the corresponding connector plugs and each of said connector sockets is aligned with a corresponding one of said connector plugs, whereby any number of said electrical devices are adapted to be plugged together in series.
 5. A device as claimed in claim 1, further comprising a cable shoe arranged substantially in said housing and seated on one of said terminal screws whereby said shoe is fastened to oNe of said strips.
 6. A device as claimed in claim 1, further comprising a plug pin having a seat portion seated on one of said terminal screws and fastened thereby to one of said strips, said plug pin having a generally angular shape and extending from said screw to outside said housing.
 7. A device as claimed in claim 2, wherein said rivet members are located on each side of said tappet and comprise at least one tubular rivet and at least one full-bodied rivet, said front plate and said rivets forming a single piece of molded plastic.
 8. A device as claimed in claim 5, wherein each of said connector plugs has a lateral recess and each of said connector sockets comprises a curve spring arranged in a corresponding one of said ledge members, each of said springs having a catch portion for engaging the recess in the connector plug of another of said electrical devices. 